Traction apparatus for motor vehicles



June 25, 1940. A. L. FISCHER TRACTION APPARATUS FOR MOTDR VEHICLES 3Sheets-Sheet l Filed Nov. 6, 1939 June 25, 1940. A. l.. FISCHER TRACTIONAPPARATUS FOR MOTOR VEHICLES Filed NOV. 6, 1939 3 Sheets-Sheet 2Invenlor,

June 25, 1940. A. L. FISCHER 2,205,689

TRACTION APPARATUS FOR MOTOR VEHlCLES Filed Nov. 6, 1959 Patented June25, 1940 Unirse stares TRACTION APPARATUS FOR MOTOR VEHICLES alfred L.Fischer, Portland, Maine application November 6, 1939, Serial No.`303,999

solsims. loi 152-214) u .each rear wheel of the vehicle, is attached toi The invention hereinafter' to be described relates, generally, totraction devices for motor vehicle tires, but deals more specificallywith apparatuswhich may be installed on the rear axle housing and soarranged that it may instantly be put into or drivers seat.

When not in active service the traction eleout of operation from thements may be conveniently stored in the space` between the tire and themud-guard of the vehicle.

I am aware of the fact that, heretofore, others have undertaken toevolve a satisfactorily operating mechanism, seeking the same objectivesas I have in my present invention; but insofar as I have knowledge noworkable and: at the saine time practicable combination has as yet beendevised.

The conventional type ci circumferential tire chain, or the transversely`applied mud-hooks haveinot solved the problem, being very decient onicy surfaces and objectionable for the reason that they soon wear outwhen used on paved or cement road surfaces.

In the snowbelt portions of the country the highways are usually wellbroken outimmediately aiteieach storm, leaving the surface of the roadpracticaliy bare. Winds, however, undo the work of the highwaydepartments `by returning the snow to the road-bed in many places,makthe use oi some sort` of traction device necessary.

Even so, it remains a fact that a preponderant portion of the highwaycould be negotiated with- `out traction aids, but because portions -ofthe road, even though a very small part of the whole, require their use,the vehicle must he equipped with them before the motorist starts on histrip.

And it will be apparent to those having knowlledge oi suchmatters thatputtingvon and taking off tire chains, according to the demands andrequirements of the road conditions met with,

. would be a very irksome task, to avoid which the average motoristwouid keep them `on throughout his trip'with the result that the lifevoi the chain would be very brief;

Cognizant of the fact that the present-clay,

conventional i type of traction device does not fully qualify, and thatthere seems to be a growing demand for a mechanical arrangement whichcanbe thrown into and out of action instantly, at the will of theoperator of' the vehicle, I have conceived an idea which I have put intopractice anddemonstrated its feasibility.

-The apparatus, supplied in two units, one for vide an eiiicienttraction device.

the rear-axle housing. IIhe traction element itself may be positioned onthe periphery of the tire in response to a simple movement of a leveroperated from the drivers seat, and a reverse movement of this leverdisengages the traction element from the tire and houses it between thetireand the mud-guard.

As the brake-drums are usually integral with the axle housing it isnecessary lto provide the parts to be` rigidly attached to the vehiclein halves, boiting them together. They may thus be 'readily removed atthe end of the winter season, if thought desirable, or they may remainon the motor vehicleas an accessory therefor.

The primary object of my invention is to pro- Another objeot,of slightlyless importance, concerns its ability `to be placed in and out ofcommission a third `resides in description found in the followingspecification,

taken in connection with the accompanying drawings disclosing apreferred embodiment thereof. Y

n the drawings, in which like reference characters are employed toidentify like parts: n

Fig. l is aside elevation of my traction apparatus, the traction-shoebeing shown engaging the tire;` Y

Fig. 2 is an enol elevation thereof, as viewed from arrow A, Fig. l;

Fig. 3 is a detail dealing with the actuating lever and toggle-baroperating rod;

Figs. 4 and 5 show, diagrarnmatically`,` progressive steps taken to moverthetraction-shoes from the tire;

Fig. 6 illustrates the action of the tractionshoe asit rst contacts theground surface;

' Fig. 7 is a sectional elevation ofthe device, the section being takenon line 'l-, Fig. l., with the traction-shoe shown on the top of thetire;

Fig. 8 is a side elevation of the tractiomshoecarrying frame;

Fig. `9is a fragmentary plan view of Fig. v8;

Fig. 10 is an outside plan view of the trac-V tion-shoes," not bent tovfdt the tire Fig, 11 shows the blank for an alternateform crosssection, the rear axle housing upon which.

the apparatus is primarily supported.

Secured to this rear axle housing is a split, flanged-hub or sleevemember I, the two parts of which are clamped together by bolts 2.

Rising on opposite sides, respectively, of the flange portions of thismember I are two small, axially parallel cylinders 3, in each of whichis reciprocably disposed a plunger 4. The tops of the two plungers areinterconnected by a crossbeam 5 which is subject to radial but Vnotrotatable movement. f l

Continuing outwardly along the housing" from the flange portion is amachined turned sleeve portion Ia on which is mounted a rotatabletraction-shoe-carrying frame structure, embodying a ring 6 with acylinder 6a, on each side, and in each cylinder a plunger l.v The ring tis split and the two halves are mutually joined by bolts 8.

The upper ends of plungers 'I are interconnected by atraction-shoe-carrying plate 9 having on its inner face atraction-shoe-lifting stud Ill.

One side of the ring 5' thrusts on the shoulder Ib of the sleeve Ia, andthe opposite side on the split thrust collar II, the two parts of whichare clamped to the sleeve la. by bolts I2.

Members I, Ia and II are fixed against rotation, but the split ring Gmayrevolve on the sleeve Ia. Y

It will be noted that the two sets of cylinders 3, 3, and 5d, 6a, serveas the guide members, and

the cooperating sets of plungers, il,V il, and l, 1,

respectively, are the guided members in the two mechanisms. It isobvious, however, that various other forms of structure might beemployed for this purpose, vone of which would be side seams looseenough for the parts to easily slide.

In Fig. 10 I illustrate in outside plan view my traction-shoe structure.It comprises a plurality of diamond shape plates I3, arcuate bothlongitudinally and transversely. Each plate is equipped with an insidehanger l3nt which is secured to the face 9a of the plate 9, and with anoutside hanger I3b fixed Vto a tie-rod i4, as shown. An alternateconstruction (see Fig. Il), would be to make the plates, the innerandouter hangers and the outer connecting bar labcorresponding to thetie-rod Illof a one-piece stamping. It will be observed by reference toFigs. 6 and '7 that the traction-shoes or plates I3 normally contact thetire at the points m, .'12, and y, y, leaving the central portion of theplate slightly spaced from the surface of the tire, as seen at O. Ontheinside of the plate I3,` at each end thereof, are small tire-grippingelements I5, and on its outer, central portion are larger,vgroundgripping members I'.` It is to be particularly noted that theoutside end portions of ythe shoe plates are smooth. By reference toFig. 6 the object of this construction will be apparent.

Assume that the tire T is advancing in the direction indicated by arrowB, and rotating as indicated by arrow C. When the shoe i 3 is about `tocontact the ground G, its smooth outside end portion |30 offerspractically no. resistance to wedging itself under the tire, aided as itis by the inside, tire-gripping elements l 5. When the shoe has moveddirectly under the center of the tire the weight of the vehicle causesthe tireto slightly straighten out the shoe plate, and this results inthe gripping elements I5 more rmly and positively engaging the surfaceof the tire,-

largely eliminating slippage between the contacting members.

But there is another element, the spring Il, which being always undertension is largely relied upon to hold the shoe plates I3 in strongengagement with the tire surface when the device is in active service.This spring may, if desired, be protected by a exible sheath Ia.

Thus the two forces, the power of the spring Il and the slip-resistingaction of the elements I5, combine to secure the shoe plates to the tireand give to the outside ground-gripping elements I 6 a maximum drivingpower for the traction apparatus.

It will be'understood, of course, that the gripping elements I5 are soconstructed as to avoid injury to the tire, their function being tosimply indent the more or less soft rubber of the tire rather thanpuncturing it.

In describing the action of my traction apparatus reference should rstbe had to Fig. l which shows one of the traction-shoe units, composedpreferably of three plates although this may be varied, tightly bound tothe tire T by the spring II.

As the tire revolves in the direction of arrow D the shoe can freelyrevolve in its orbit, contacting the ground at each revolution of thewheel, the traction-shoe lifting stud Iii clearing the beam 5 and itsassociated parts, as seen in dot and dash lines at the top of the Fig.1.

Assume that a motorist is travelling over a highway on which there aresnow-covered rstretches alternating with bare sections of roadbed. Whenhe approaches a snow-covered portion of the road he will require thetraction apparatus, but further alongl he may come upon a long stretchof bare, hard surfaced highway. He has at his immediate commandfacilities for putting the apparatus into service or out of serviceaccording to and as conditions present themselves.

Having passed the snow-covered portion of the highway, the motorist willnow proceed to put the traction element temporarily out of service byactuating the lever I8 in a direction indicated by arrow E, Fig. 3, thelever which is of the ratchet type being placed where it is easilyaccessible from the drvers seat.v

This act places a strain on and movement of the toggle-bar rod lil, theend thereof, opposite the ratchet lever, being pivotally secured at 20to the inner ends of the toggle-bars 2| and Z2,

from the Fig. 1 to the Fig. 4 position, bringing it into the path of thestud I0 which has orbital movement with the traction-shoe parts. It willbe observed that the stud I0 starts to ride the top face oi the beam 5,but in its'forward movement it also rides the top of a latch and tripmember 25, pivotally mounted at 5a on the outer side of the beam. Thehorizontal portion 25a of the angular member 25 I designate as the triparm, and the vertical portion 25D as the latch arm.

The trip arm normally rises above the radius of the top surface of thebeam were its circular form extended uninterrupted yto 'the verticalcentrai line 'I-'l. -But this radius line is broken `adjacent `the topof the beam, leaving a depression 5b for purposes to be hereinafterexplained.

On the -latch arm h is a latch hook 25o which, whenthe parts arearranged as `shown rin Fig. l, is spaced at a considerable distancebelow the stop bracket 2t but which engages this' bracket upon the firstmovement of `the ratchet Ilever i8 just described. The step bracket itis xedly secured -lto the 'outer face of the disc I and is, therefore animmovable part of `the device.

vne function of `this latch structure is -to prevent `the beam 5 risingto a `position where the stud fliD might engage its under edge 5c,incident to undertaking the iirst portion of the beamlifting operation.And to clarify the description, it might be well to state that theraising of the beam 5 is, in reality, a single complete oper-ation fromthe `time the traction-shoe is released from the rtire until it ishoused under the mud-'guard Tofmake it somewhat more understandable Ihave chosen to `describe the operation by dividing it v'into consecutivebut continuous steps. I have also, for the `'purpose `of simplifying thedrawing, made the stud lil representative of the whole swinging frameand traction-shoe parts in Figs. 4 and 5.

After the toggle-bar members have raised the beam "5 into the positionin which itis depicted in Fig. 4, the stud il) has just begun to ridethe face of the beam at lila. But continuing movement oi the stud toposition ib, makes it also ride the trip arm 25a and *lower it sucientlyto swing the latch Ahook 25o off the stop bracket 2t which would permitfurther upward movement of the beam. The next portion of the continuousupward movement of the beam 5 bringstlie stud I9 to position ISC, in thedepression 5b, the relative positions Vof the parts now being as shownin full lines, Fig. 5, the toggle-bars undergoing a still furtherstraightening out.

The traction-shoe has now been raised sumciently to give Va safe marginof clearance between the tire and the shoe; but to insure against all`contingencies I still further raise thebeam tand the stud Iii, intopositions 5r andlild respectively.

The traction-shoe at this time is locked in its extreme upward positionby the lever I8 which applies a yielclable tension on the rod I9 throughthe agency of the conventional arrangement shown in Fig. 3, wherein therod i9 isbroken, and a spring 2'! housed in a casing 28 thrusts on acollar 29 secured to one end of the rod and on the casing cover 30 toprovid yieldable extensibility t0 the rod structure.

When the final lifting operation, o r 'the operation as a Whole has beencompleted, the togglebar 2i engages a stop-pin 3l and no further upliftof the beam can be made. When the toggle-bar 2i is in dot and dash lineposition, Fig.`5, and thrusting on rthe stop-pin 3|, the lever l E is sopositioned and held bythe ratchet structure that more or lesscompression of the spring 27 takes place. The toggle-'bars are thusyieldably maintained in a stopped position and this takes care of anysla'ckness which otherwise might occur with a positive type connectionbetween the parts.

It will be noted that the points 20, 23 and 24 are never in alignment,so the toggle-bar pivotal points are never on dead center.

` To return the toggle-bars from their stopped to their 'originalpositions (or from their dot and dash line 'positions in Fig. 5 totheirfull line positiens in Fig. l.) I employ a spring 32 one end ofwhich Ais secured on the beam 5 and the other on the toggle-bar 2i.

A Wire spring element 33, one end of which is secured on the beam 5 andthe other end having tires. And in Fig. '7 the` heavy dot and dashlilies represent the face and one side of the brake drum, DD, spacebeing provided within which` toimo'unt theelements having to do withoperating the brake.

lFrom the foregoing description it is thought` fr to be apparent that atraction device constructed in accordance with my invention isparticularly Well adapted for use by reason of the convenience andfacility with which it may be operated, not only over straight awaycourses of highways but in cramped positions along the curbing of citystreets. The fact that with my design of traction device it can beattached to the vehicle at the beginning of the Winter 'season a'nd leftto remain throughout the cold weather, putting it into service at suchtimes only as it is required, saves an enormous amount of labor over theconventional `type of chain, which requires to be constantly put on andtaken off, saves' also on the Wear of thetraction `device itself, and isinstantly available when needed, gives to the apparatus such merit aswill commend itself to those who have once used it.

It is obvions that my invention is susceptible of various changes an'dmodification without departing from the principles and spirit thereof.For "this reason I do not wish to be understood as limiting myself tothe precise mechanical detail and arrangement of parts herein shown incarrying out my invention in practice except as hereinafter claimed.

What I claim is:

1. In traction apparatus for motor vehicle wheels the combination with arear axle housing anda vehicle tire, of a non-rotatable hub niemberfixed to saidi'ear axle housing, a cross-beam mounted on said hubmember, means for locating said cross-beam on said hub member in variouspredetermined radial positions distant from said axle housing, atraction-shoe-carrying frame mounted in its entirety for rotation onsaid hub member, a traction-shoe element secured at one end to saidtraction-shoe-carrying frame, the ground-contacting portion oi' saidelement aligning with and over-hanging said tire, and yields biepressure means Vconstantly acting to draw said traction-shoe elementtread or the tire.

`2. In a traction apparatus for motor vehicle wheels comprising 'incombination with a rear axle housing and tires for said Wheels, a splitsleeve xed on and adjacent each endV of said axle housing, a cross-beammounted on said' sleeve and susceptible of movement thereon transverselyof said rear axle housing, toggle-bars ininto engagement with. the

terconnecting said sleeve and said cross-beam, a toggle-bar rod foractuating said toggle-bars, a spring normally tending to draw` saidcross-beam toward said sleeve, and a latch preliminarily limiting theoutward, radial movement of said crossbeam during the iirst portion ofthe movement of said toggle-bar rod toward aligning said togglebars.

3. In a traction device for motor vehicles the combination with a rearaxle housing and a wheel tire, of a anged sleeve member xed on said axlehousing, a cross-beam on said flanged sleeve member, susceptible ofradial movement, only, thereon, a traction-shoe-carrying frame adapted Yto rotate around said flangedsleeve member, said frame including a ring,a traction-shoe-attaching plate movable radially on saidtraction-shoe-carrying frame, and a spring tending to bias the moveme-ntof said attaching plate in one direction normally drawing thetraction-shoe on to said tire, a lifting-stud in said attaching plate,alifting-stud locking depression in the upper face of saidcross-beam,and means, operable by the driver of the vehicle, predeterminately tomove said cross-beam into the path of travel of the liitingstud andcause said traction-shoe to be forced from the tire, or conversely, topermit said crossbeam to recede toward the .axle housing and therebyallow the traction-shoe to draw into close engagement with the tire.

4. In a traction apparatus for a motor vehicle wheel the combinationwith a rear axle housing and a vehicle tre,of a split, flanged-hubmember, means to xedly secure said flanged-hub member to said rear axlehousing, a cross-beam associated with said flanged-hub member,interconnected guide elements on Asaid flanged-hub member and saidcross-beam, enabling movements of said cross-beam, in directions towardand from said rear axle housing, to be made, a traction-shoe-carryingframe revolubly mounted on said iianged-hub member, a traction-shoesecured to and extending outwardly from said traction-shoe-carryingframe, a traction-shoe-liiting stud on said traction-shoe-carrying framead-apted at predetermined times, to be engaged by said cross-beam to theend that said traction-shoe may be forced off the tire, a toggle-barunit, embodying two members mutually and pivotally joined, with theirouter ends pivotally connected to the said split, anged-hub member andsaid cross-beam, respectively, and an ractuating rod making connectionwith said toggle-bar unit, and manipulated by the operator of thevehicle.

5. In a traction device for a motor vehicle wheel, the combination witha rear axle housing and a tire for said wheel, of a sleeve xed on saidIrear axle housing, a cross-beam mounted for lim.- ited radial movementon said sleeve, means to radially move said cross-beam, atraction-shoecarrying frame revolubly mounted on said sleeve,

one side of which is yieldingly secured to said,

" traction-shoe-carrying frame, the ltraction shoe proper revolving in aVertical plane coincidentV .with that of the tire, a spring normallytending to hold said 'traction shoe in engagement with said tire,toggle-bars interconnecting said crossbeam and said sleeve, and means toactuate said toggle-bars to the end that the face of said crossbeam maybe brought into the path of rotation of said traction-shoe-lifting stud,and thereby cause said traction-shoe to be moved from the face of thetire, and suspended in space thereabove.

6. In a traction device for the tire of a motor vehicle the combinationwith a rear axle housing, of a cross-beam xed on said housing and havinga convex face interrupted by a depression therein, means to raise andlower said cross-beam various distances from said housing, atraction-shoe-carrying frame mounted to revolve around said rear axlehousing, a traction-shoe, having connection with saidtraction-shoe-carrying frame, disposed in the plane in which rotatessaid tire, a spring normally drawing said traction-shoe toward said tireand at-predetermined times to bring it into strong engagement therewith,a traction-shoelifting stud in said traction-shoe-carrying frameadapted, when said cross-beam is brought into engagement therewith toraise said traction-shoe oi said tire, and means to predeterminatelymaintain said traction-shoe in its off-the-tire position.

'7. A traction apparatus for a motor vehicle wheel tire comprising incombinationwith the rear axle housing for said vehicle, a cross-beammounted superjacent said rear axle housing, means to raise and lowersaid cross-beam, said means being operable from` the drivers seat, atraction-shoecarrying frame mounted torevolve around said housing, atraction-shoe adjustably secured to said'traction-shoe-carrying frameand disposed in the plane of said tire, said traction-shoe embodying atwo-way-arcuate plate of substantially diamond shape, having smoothoutside end surfaces and coarse, ground-gripping elements on itscentrally disposed surface with ne tire engaging elements, a springnormally drawing said traction-shoe toward the tire, and a lifting studon said traction-shoe-carrying frame adapted to be engaged by saidcross-beam when said crossbeam is raised for the purpose of disengagingsaid traction-shoe from said tire.

8. A device oi the class described adaptedl for mounting on the rearaxle housings of a motor vehicle having tires thereon, comprising a hubportion on each of said rear axle housings, a machine-turned part oneach of saidl hub portions, a cross-beam mounted on said hub portion,means to reciprocate said cross-beam to and from said hub portion, atraction-shoe-carrying frame mountedto revolve on said machine-turnedportion oi said hub portion, a traction-shoe unit structure yieldinglymounted on said frame and disposed in a plane in which rotates saidtire, a traction-shoe-lifting stud in said frame, said stud travellingin an orbit in which lies said crossbeam, means to bring said cross-beaminto and out of engagement with said stud, said operation beingperformed from the vehicle drivers seat, a springv adapted to provide aconstant tension, on said traction-shoe tending to hold it in engagementwith the said tire, and means on said crossbeam for seating saidtraction-shoe-lifting stud,

when raised by said cross-beam, the seating of said stud in said seatmaintaining the tractionshoe out of contact with the tire.

l L. FISCHER.

